Flutter Appbar (actions) with child tabs

Question

I'm new in Flutter and I wonder if you can help me to find a solution to my problem.

I have a scaffold with a tabview and I want to make a filter (actions button) in the main appbar to manage tabs.

Both main and child are StatefulWidgets

here's my code of the main page :

Widget body = TabBarView(
      controller: tabController,
      children: <Widget>[
        new First(filter: filter),
        new Second(filter: filter);
        new Third(filter: filter);
      ],
    );
return Scaffold(
    appBar: AppBar(
           actions:[IconButton(icon: Icon(MdiIcons.filter),onPressed: 
           () {
              // Send info to child 
           })],
           bottom: new TabBar(
           controller: tabController,
           tabs: <Tab>[
             new Tab(text:"Tab1"),
             new Tab(text:"Tab2"),
             new Tab(text:"Tab3")
           ],
    body: new Builder(builder: (BuildContext context) {
      _scaffoldContext = context;
      return body;
    }));
));

Children page :

Widget body = Text("Filter name here");
return Scaffold(
  body: 
  new Builder(
    builder: (context) {
      snack = new DisplaySnackBar(context: context);
      return body;
    }),
);
}

I don't know where to put the actions of appbar to make Text on child's body changes from the main page.

Answer 1

I found the solution by making my parent widget as an InheritedWidget so I can access to it's data from child.

Here's an example :

class MyStatefulWidget extends StatefulWidget{
@override
  MyStatefulWidgetState createState() => MyStatefulWidgetState();

  static MyStatefulWidgetState of(BuildContext context){
    return (context.inheritFromWidgetOfExactType(_MyInheritedStateContainer) as _MyInheritedStateContainer).data;
  }
}
class MyStatefulWidgetState extends State<MyStatefulWidget>{

String variableCalledHello = "Hello World";
@override
  void initState() {
    super.initState();
  }
 @override
  Widget build(BuildContext context) {
   return new _MyInheritedStateContainer(data:this,child:/* Body here */);
  }
}
class _MyInheritedStateContainer extends InheritedWidget{
    _MyInheritedStateContainer({
Key key,
    @required Widget child,
    @required this.data,
  }) : super(key: key, child: child);

final MyStatefulWidgetState data;

 @override
  bool updateShouldNotify(_MyInheritedStateContainer oldWidget) {
    return true;
  }
}

and for every child :

you just have to call MyStatefulWidgetState state = MyStatefulWidgetState.of(context);

example :

@override
  Widget build(BuildContext context) {
   MyStatefulWidgetState state = MyStatefulWidgetState.of(context);

   print(state.variableCalledHello);

   return /* Container ... */;

}

Hope that will help someone to solve his problem.

Thanks.